Polyembryony, Biology

Assignment Help:

Polyembryony

Presence of more than one embryo in a seed is termed polyembryony. The phenomenon, first discovered in orange seeds by Leeuwenhoek (1719), attracted considerable attention because of its potential for application in and horticulture. Polyembryony is broadly classified into simple and multiple, depending on whether the supernumerary arises in one or more embryo sacs in the ovule. Simple polyembryony may be sexual or asexual. In sexual polyembryony embryos may originate from the fertilized egg and synergids, or by budding or cleavage of the polyembryony cells or suspensor of the zygotic embryo.

Asexual embryos are produced within the embryo sac without fertilization. Embryos may also originate from diploid nucellar or integumentary cells of the ode and grow into the embryo sac. These embryos are termed adventive or sporophytic. Multiple polyembryonies involve production of accessory embryos from two or more embryo sacs in the same ovule. For example, in the sea Island cotton, Gossypium barbadense, fertilization of egg in one embryo sac stimulates the induction of embryo from an unfertilized egg in the adjacent embryo sac within the same ovule. Thus, diploid-haploid twin embryos are produced in the seed.


Related Discussions:- Polyembryony

What is the cell division process, What is the cell division process direct...

What is the cell division process directly related to the embryonic growth? The embryonic growth depends directly on mitosis. By this type of cell division the zygote separates

Under which forms is the trypanosoma cruzi found, Q. Under which forms is t...

Q. Under which forms is the Trypanosoma cruzi found in its hosts? In the definitive hosts also as in triatomine bugs (intermediate hosts) the protozoan that causes Chagas' dise

What do you mean by cold deserts, What do you mean by Cold Deserts? Col...

What do you mean by Cold Deserts? Cold deserts cover a vast area north of the Himalayan ranges forming an ecosystem with exceptionally low temperatures which may reach - 75°C a

Specific considerations and applied aspects in dentistry, Specific consider...

Specific considerations and applied aspects in dentistry The dental chair and delivery system. The chair should be smooth and seamless. The greatest potential for cross contami

Types of retaining structure, What are the types of evaluation of lateral e...

What are the types of evaluation of lateral earth forces acting on retaining structures? This section seeks to introduce you to the evaluation of lateral earth forces acting on

How are the transparency and functions of cornea evaluated, How are the tra...

How are the transparency and functions of cornea evaluated? Physiological roles of barrier function, refractive function (with interaction of tear film), response to wound and

Are the extraembryonic membranes the same in all vertebrates, Q. Are the ex...

Q. Are the extraembryonic membranes the same in all vertebrates? The presence of each extraembryonic membrane differs according to the vertebrate class. In amphibians and fi

Determine the effective spring constant of the molecule, A Molecule of DNA ...

A Molecule of DNA is 2.17 um long. The ends of the molecule become strongly ionixed: negative on one end, positive on the other. The helical molecule acts like a spring and compres

Explain control function of organic molecules, What are some examples of th...

What are some examples of the control and informative function of organic molecules? Based on genetic information, organic molecules control the whole work of the cell. The nuc

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd